Prosthetic knee implant systems and methods with linked tibial rotation

ABSTRACT

A tibial spacer paddle comprises a spacer block comprising opposing bearing surfaces, an alignment slot extending into the spacer block; and a handle extending from the spacer block. The spacer block can include feet for passively engaging the femur or pegs for actively engaging a femoral component so that the spacer block is linked to the femur while the tibia rotates. A tibial spacer system comprises a provisional component having an alignment tab extending from a body and an alignment indicator located on the body, a femoral component and a pin extending from the femoral component. The pin can engage the alignment tab so that the provisional component is linked to the femur while the tibia rotates. In addition to or alternatively to the alignment tab and pin, the provisional component can include a tibial plate that can be rotationally connected to the provisional component.

CLAIM OF PRIORITY

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/464,076, filed on Feb. 27, 2017, the benefit ofpriority of which is claimed hereby, and which is incorporated byreference herein in its entirety.

TECHNICAL FIELD

This document pertains generally, but not by way of limitation, toorthopedic implant systems and methods for knee arthroplasty. Moreparticularly, this disclosure relates, but not by way of limitation, toorthopedic devices and methods for matching internal/external rotationof a tibial component to that of a femoral component.

BACKGROUND

A natural knee joint typically undergoes a degree of rotation betweenthe tibia and the femur during flexion. Specifically, the femur canrotate in a transverse plane relative to the tibia. Thus, it can bedesirable to replicate the natural rotational alignment of the tibia andfemur when implanting one or more orthopedic femoral and tibialcomponents.

Frequently the rotation of the tibial component is set independently ofthe femoral component, and solely based on tibial bony landmarks. Insome cases, this can result in mal-rotation of the tibial component withrespect to the femoral component. In these cases, if a highly conformingarticulation design between femur and tibia is used, when the prosthesisis loaded, the mating tibial-femoral articulating surfaces will drivethe tibial component into rotational alignment with the femoralcomponent. This shifting of the tibial component will in turn rotate theentire tibial bone into a non-physiologic orientation with respect tothe femur. This can result in pain, stiffness, and a knee that does notfeel normal.

Some surgeons have attempted to match natural tibial rotation by atechnique called “floating the tibia.” In this approach, the femoraltrial can be placed and a trial reduction can be performed with thetibial bearing placed in a tibial sizing tray that is free to rotate andtranslate on the surface of the proximal tibial resection. The tibialsizing tray is thus free to “float” between the resected tibia and thefemoral trial. The knee is taken through a range of motion and then outto full extension. The surgeon can then use a pen or Bovie to mark apoint on the tibial bone corresponding to the front of the tibial sizingplate. The assumption inherent in this approach is that the conformitybetween the bearing and the femoral component will force the bearing(and thus the tibial sizing plate) to shift into rotational alignmentwith the femoral component.

Examples of prosthetic knee implants are described in U.S. Pat. No.5,782,925 to Collazo et al. and U.S. Pat. No. 9,211,189 to Earl et al.

OVERVIEW

The present inventors have recognized, among other things, that therecan be problems associated with attempting to match the natural rotationof the tibia to the femur using the “floating tibia” technique. First,when the knee is taken out to full extension, the tibial component canbe under compressive load from the femur which can inhibit relativemotion of the tibial component on the tibial bone. Second, contemporarytotal knee arthroplasty (TKA) articulations can be designed with ameasure of rotational laxity. There can be insufficient conformity forthe femoral component to drive movement of the tibial component,particularly when it is under compressive load. Third, when the surgeonmarks the point on the anterior bone denoting the front of the tibialtrial, there is typically no corresponding mark at the posterior tibiato define the axis of rotation. The surgeon can align to the front mark,but needs to estimate where the posterior of the tibial trial wasoriented.

The present subject matter can help provide a solution to variousproblems associated with matching the natural rotation of the tibia tothe femur when implanting prosthetic knee components.

In an example, the present subject matter can help provide a solution tothese problems, such as by providing a tibial spacer paddle that cancomprise a spacer block, first and second feet, first and secondalignment chamfers, an alignment slot, and a handle. The spacer blockcan comprise a first bearing surface, a second bearing surface disposedopposite the first bearing surface, and an edge periphery regionconnecting the first bearing surface and the second bearing surface. Thefirst foot can extend from the first bearing surface at the edgeperiphery region. The second foot can extend from the first bearingsurface at the edge periphery region spaced from the first foot. Thefirst alignment chamfer can extend into the edge periphery region andthe second bearing surface opposite the first foot. The second alignmentchamfer can extend into the edge periphery region and the second bearingsurface opposite the second foot. The alignment slot can extend into theedge periphery region opposite the first and second feet. The handle canextend from the spacer block.

In another example, a tibial spacer system can comprise a spacer block,a first peg, a second peg, an alignment slot and a handle. The spacerblock can comprise a first bearing surface, a second bearing surfacedisposed opposite the first bearing surface, and an edge peripheryregion connecting the first bearing surface and the second bearingsurface. The first peg can extend from the first bearing surface. Thesecond peg can extend from the first bearing surface spaced from thefirst peg. The alignment slot can extend into the edge periphery region.The handle can extend from the spacer block.

In yet another example, a tibial spacer system can comprise aprovisional component and a sizing extension. The provisional componentcan comprise a body, an articulating surface positioned on the bodyconfigured to engage condylar surfaces of a femoral component, and analignment tab extending from the body. The sizing extension can extendfrom the body opposite the articulating surface. The sizing extensioncan comprise a bone engagement surface, an edge periphery regionextending from the bone engagement surface, and a first alignmentindicator located on the edge periphery region of the sizing extension.

In still another example, a tibial spacer system can comprise aprovisional component, a trial bearing and a pivot coupling. Theprovisional component can comprise an articulating surface configured toengage condylar surfaces of a femoral component, a first bearing surfacedisposed opposite the articulating surface, and a first edge peripheryregion connecting the articulating surface and the first bearingsurface. The trial bearing can comprise a bone engagement surface, asecond bearing surface disposed opposite the bone engagement surface,and a second edge periphery region connecting the bone engagementsurface and the second bearing surface. The pivot coupling can connectthe first bearing surface and the second bearing surface. The pivotcoupling can be configured to permit the trial bearing to rotaterelative to the provisional component.

This overview is intended to provide an overview of subject matter ofthe present patent application. It is not intended to provide anexclusive or exhaustive explanation of the invention. The detaileddescription is included to provide further information about the presentpatent application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tibial spacer paddle having alignmentfeet and an indicator groove.

FIG. 2 is a side view of the tibial spacer paddle of FIG. 1 showing anangle of the alignment feet relative to a bearing surface.

FIG. 3 is a top view of the tibial spacer paddle of FIG. 1 showing alocation for the indicator groove.

FIG. 4A is a side view of the tibial spacer paddle of FIGS. 1-3 insertedbetween a resected tibia and a resected femur in approximately sixtydegrees of flexion.

FIG. 4B is a posterior view of the tibial spacer paddle of FIG. 4Ashowing the alignment feet engaged with posterior resected surfaces ofthe femur.

FIG. 4C is a side view of the tibial spacer paddle of FIG. 4A shown withthe tibia in full extension.

FIG. 4D is an anterior perspective view of the tibial spacer paddle ofFIG. 4C illustrating natural rotation of the tibia.

FIG. 4E is an anterior perspective view of the tibial spacer paddle ofFIG. 4D with a marking of the resected tibial surface at the indicatorgroove.

FIG. 4F is an anterior perspective view of the resected tibia of FIG. 4Eshowing the marked resected tibial surface.

FIG. 5 is a perspective view of a tibial spacer paddle having alignmentpegs and an indicator groove.

FIG. 6 is a top view of the tibial spacer paddle of FIG. 5 showing alocation for the indicator groove.

FIG. 7 is a perspective view of the tibial spacer paddle of FIG. 5 and afemoral component engaged with the alignment pegs.

FIG. 8A is a perspective view of the femoral component of FIG. 7attached to a resected femur and the tibial spacer paddle of FIG. 5inserted between the femoral component and a resected tibia inapproximately sixty degrees of flexion.

FIG. 8B is a side view of the femoral component and tibial spacer paddleof FIG. 8A being moved toward full extension so that the alignment pegsalign with corresponding ports in the femoral component.

FIG. 8C is a perspective view of the femoral component and tibial spacerpaddle of FIG. 8B in full extension with the tibia rotated into anatural alignment position so that a resected tibia surface can bemarked at the indicator groove.

FIG. 9A is a perspective view of a femoral component attached to aresected femur and a tibial sizing system comprising a provisionalcomponent and a sizing plate aligned for insertion onto a resectedtibia.

FIG. 9B is perspective view of the femoral component and the tibialsizing system of FIG. 9A with the tibial sizing system inserted betweenthe femoral component and the resected tibia in extension.

FIG. 9C is perspective view of the femoral component and the tibialsizing system of FIG. 9B with the femur in full extension and the tibiarotated so a pin extending into the femoral component aligns with a tabon the tibial provisional component.

FIG. 9D is a perspective view of the femoral component and the tibialsizing system of FIG. 9B with the pin extending along the tab andalignment markings on the tibia.

FIG. 9E is a perspective view of the resected tibia of FIG. 9D showingthe sizing plate of the tibial sizing system disposed on the resectedtibia surface.

FIG. 10 is a perspective view of another embodiment of the tibial sizingsystem of FIG. 9A wherein the provisional component and sizing plate areintegrated into a monolithic component.

FIG. 11 is a perspective view of a femoral component attached to aresected femur and a tibial sizing system comprising a provisionalcomponent and a tibial plate with a pivot mount inserted between thefemoral component and a resected tibia.

FIG. 12 is a perspective view of the tibial plate of FIG. 11 showing thepivot mount comprising a peg.

FIG. 13 is a top perspective view of the provisional component of FIG.11 showing an engagement tab.

FIG. 14 is a bottom perspective view of the provisional component ofFIG. 11 showing cut-backs of an engagement surface.

FIG. 15A is a perspective view of the femoral component of FIG. 11attached to the resected femur and the tibial sizing system explodedfrom the resected tibia.

FIG. 15B is a perspective view of an assembled tibial sizing system ofFIG. 15A inserted between the femoral component and the resected tibiawith the tibia rotating into natural alignment so that a pin extendingfrom the femoral component aligns with a tab on the provisionalcomponent.

FIG. 15C is a perspective view of the tibia of FIG. 15B in fullextension so that the pin is fully seated in the tab and the resectedtibia is marked with alignment markings.

FIG. 16 is a top perspective view of another embodiment of theprovisional component of FIGS. 13 and 14 without an alignment tab.

FIG. 17 is a bottom perspective view of the embodiment of theprovisional component of FIG. 16 without the alignment tab.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of tibial spacer paddle 10 having alignmentfeet 12A and 12B and indicator groove 14 disposed in spacer block 16.FIG. 2 is a side view of tibial spacer paddle 10 of FIG. 1 showing anangle of alignment feet 12A and 12B relative to bearing surface 18A.FIG. 3 is a top view of the tibial spacer paddle of FIG. 1 showing alocation for the indicator groove 14. FIGS. 1-3 are discussedconcurrently.

Spacer block 16 can include first bearing surface 18A, second bearingsurface 18B, edge periphery surface 20, notch 22 and handle 24. Edgeperiphery surface 20 can include chamfers 26A and 26B opposite alignmentfeet 12A and 12B, respectively. Notch 22 and indicator groove 14 canextend into spacer block 16 to form first condylar portion 28A andsecond condylar portion 28B. Handle 24 can extend from edge peripherysurface 20 of spacer block 16 and can include first segment 30A andsecond segment 30B.

Spacer block 16 is configured to be inserted or otherwise disposedbetween surfaces, particularly resected surfaces, of a tibia and femur,as shown in FIGS. 4A-4E. First bearing surface 18A can be configured toface toward a tibia and second bearing surface 18B can be configured toface toward a femur. First segment 28A and second segment 28B can beconfigured to align with condyles of the femur. Edge periphery surface20 can be shaped so that first segment 28A and second segment 28B canengage medial and lateral condyles of left and right leg femurs. Inother examples, spacer block 16 can be configured specifically for aleft or right leg knee. As will be discussed in greater detail belowwith reference to FIGS. 4A-4F, indicator groove 14 can provide anindication of the rotational alignment between the tibia and the femuras the tibia moves through extension and flexion in order to providealignment information for implantation of prosthetic femoral and tibialcomponents.

Alignment feet 12A and 12B can be located at edges of first segment 28Aand second segment 28B, respectively, of bearing surface 18A so as toextend from edge periphery surface 20. In examples, alignment feet 12Aand 12B are positioned to be located at a posterior side of the tibiaand femur. Chamfers 26A and 26B are disposed opposite feet 12A and 12B,respectively, in bearing surface 18B and remove a portion of spacerblock 16 at edge periphery surface 20 so that the tibia can be rotatedagainst second bearing surface 18B. Notch 22 can extend between firstsegment 28A and second segment 28B in order to provide visibility of thetibia. In an example, chamfers 26A and 26B can form an angle θ1 (FIG. 2)with bearing surface 18B of approximately one-hundred-thirty-fivedegrees.

Handle 24 can extend from edge periphery surface 20 to provide structurefor a surgeon to handle and manipulate spacer block 16. Handle 24 canextend from an anterior portion of spacer block 16 so that tibial spacerpaddle 10 can be inserted into an incision in an anterior portion of aknee joint. If desired, an instrument, such as a retractor, can be usedto hold tibia T and femur F in a retracted position to allow forinsertion of tibial spacer paddle 10. Handle 24 can extend from edgeperiphery surface 20 offset from a center of spacer block 16 to providespace for placement of indicator groove 14, which can be placed at thecenter of spacer block 16. First segment 30A of handle 24 can extendfrom second portion 28B of spacer block 16 at posterior end 32A. Firstsegment 30A can be curved toward indicator groove 14 so that anteriorend 32B is brought closer to indicator groove 14. Second segment 30B canbe attached to anterior end 32B so that second segment 30B substantiallyaligns with alignment slot 14. Anterior end 32B can be planar and canextend parallel to indicator groove 14. Second segment 30B can comprisean elongate body having a central axis A1 that is configured to extendaxially in the direction of indicator groove 14. Handle 24 thereforeprovides an indication of the center of spacer block 16 and points inthe direction of indicator groove 14 to provide a surgeon with tactileindicator for the orientation of tibial spacer paddle 10. Second segment30B can include access bores 34A and 34B that can provide variousfunctions, such as to allow tools or instruments to be inserted throughhandle 24.

Bearing surface 18A can be configured to face a resected tibia surface.Bearing surface 18B can be configured to face a resected femur surface.The resected tibia and femur surfaces can be planar or nearly planar.Bearing surfaces 18A and 18B can also be planar or nearly planar so asto readily slide against the resected tibia and femur surfaces.Indicator groove 14 can extend all the way through spacer block 16 fromfirst bearing surface 18A to second bearing surface 18B so that theresected tibia can be accessed through indicator groove 14. Indicatorgroove 14 can be tapered between first bearing surface 18A and secondbearing surface 18B. Indicator groove 14 can be wider at first bearingsurface 18A than at second bearing surface 18B. As such, indicatorsurface can be configured to guide an instrument, such as a pen, Bovie,marker, scalpel or pick, toward the tibia. The greater width ofindicator groove 14 at first bearing surface 18A can facilitateinsertion of the instrument by a surgeon into indicator groove 14, whilethe narrower width of indicator groove 14 at second bearing surface 18Bcan facilitate guidance of the instrument to a more precise location onthe tibia.

Alignment feet 12A and 12B can be configured to hold spacer block 16into engagement with the resected femur. Posterior surfaces 36A and 36Bcan extend from first bearing surface 18A at right angles or near rightangles. However, in other examples, posterior surfaces 36A and 36B canextend at other angles relative to bearing surface 18A for use withsurgical procedures where the resected femur surface is notperpendicular to a resected flat anterior surface of the femur (as shownin FIG. 4A). Thus, bearing surface 18A can remain engaged with a distalresected surface of the femur while posterior surfaces 36A and 36B canremain engaged with posterior resected surfaces of the femur. Ifdesired, a surgeon can grasp handle 24 to facilitate engagement ofspacer block 16 and the femur. As the tibia moves from flexion toextension, the tibia can rotate against bearing surface 18B alongvertical axis A2, as described in greater detail with reference to FIGS.4A-4F.

FIG. 4A is a side view of tibial spacer paddle 10 of FIGS. 1-3 insertedbetween resected tibia T and resected femur F in approximately sixtydegrees of flexion as defined by angle θ2. Resected tibia T can includeproximal surface S1. Resected femur F can include distal surface S2,first posterior surface S3A, second posterior surface S3B, angledanterior surface S4, first quarter surface 55A and second quartersurface S5B. Tibia T and femur F can be resected using any conventionalresection process. Tibial spacer paddle 10 depicted in FIGS. 1-3 isconfigured to be used with the resected surfaces shown in FIGS. 4A-4F.However, tibial spacer paddle 10 can be used with other resections.Additionally, tibial spacer paddle 10 can modified to be used with otherresections. Tibial spacer paddle 10 can be configured in variousembodiments to allow rotation of one of tibia T and femur F againsttibial spacer paddle 10 while having surfaces that permit tibial spacerpaddle 10 to be held in flush engagement with the other of tibia T andfemur F.

With tibia T and femur F in flexion, tibial spacer paddle 10 can beinserted between distal surface S2 of Femur F and proximal surface S1 oftibia T. For example, tibia T and femur F can be positioned intoapproximately sixty degrees of flexion to receive tibial spacer paddle10, as defined by angle θ2, between femur axis AF and tibia axis AT. Asurgeon can grasp handle 24 to insert spacer block 18 into an incisionin a knee of a patient and further into a space between tibia T andfemur F. Alignment feet 12A and 12B can be slipped around distal surfaceS2 to engage first and second posterior surfaces S3A and S3B. Bearingsurface 18A can be positioned against distal surface S2. Chamfers 26Aand 26B can be positioned to contact proximal surface S1. With femur Fand tibia T disposed in sixty degrees of flexion, as shown in FIG. 4A,chamfers 26A and 26B will be slightly canted with respect to proximalsurface S1 such that an edge of chamfers 26A and 26B and edge peripherysurface 20 is engaged with proximal surface S1. In other words, if femurF and tibia T were disposed in forty-five degrees of flexion, chamfers26A and 26B would be flush with proximal surface S1 due to angle θ1being one-hundred-thirty-five degrees.

FIG. 4B is a posterior view of the tibial spacer paddle 10 of FIG. 4Ashowing alignment feet 12A and 12B engaged with first posterior surfaceS3A and second posterior surface S3B of femur F. Notch 22 is shownbetween feet 12A and 12B and shows proximal surface S1 therebetween.Bearing surface 18A is shown engaged with distal surface S2. As such,feet 12A and 12B can be rotated on proximal surface S1 as tibia Trotates relative to femur F as tibia T and femur F move betweenextension and flexion. Tibial spacer paddle 10 can remain engaged withtibia T due to pressure applied by tendons and ligaments connectingtibia T and femur F.

FIG. 4C is a side view of tibial spacer paddle 10 of FIG. 4A shown withtibia T in full extension. As tibia T moves into full extension from theflexion position of FIG. 4B, tibia T rotates so that bearing surface 18Bengages proximal surface S1 of tibia T. With bearing surface 18A alreadyengaged flush with distal surface S1, spacer block 16 can be positionedsquarely between distal surface S1 and proximal surface S1. Feet 12A and12B keep the rotational orientation of tibial spacer paddle 10 constantwith respect to the axis of femur F, thereby allowing tibia T to rotatealong the axis of tibia T against bearing surface 18B as tibia T movesinto extension. Indicator groove 14 points to a portion of tibia T thatshows where the center of femur F points to on proximal surface S1, thusshowing the natural rotational position of tibia T relative to femur F.

Spacer block 16 can have a thickness between bearing surface 18A andbearing surface 18B that can be matched to various prosthetic devices.For example, the thickness can be equal to the total thickness of afemoral component and a tibial component intended to be implanted onfemur F and tibia T, respectively. The thickness of spacer block 16 canallow the ligaments and tendons of femur F and tibia T to hold spacerblock 16 in the natural tension of the knee joint. Different tibialspacer paddles 10 can be provided with different thicknesses in order toallow a surgeon to trial the knee joint for different prosthetic devicesat a desired level of tension.

FIG. 4D is an anterior perspective view of tibial spacer paddle 10 ofFIG. 4C illustrating natural rotation of tibia T. As mentioned, withbearing surface 18A flushly engaged with distal surface S2 of femur Fand bearing surface 18B flushly engaged with proximal surface S1 oftibia T, tibia T is free to rotate against spacer block 16, as shown byarrows of rotation R1 and R2. Resected surface S4 of femur F can allowaccess to indicator groove 14 for both visual inspection and insertionof a tool or instrument.

FIG. 4E is an anterior perspective view of tibial spacer paddle 10 ofFIG. 4D with marking 38 of the resected tibial surface at indicatorgroove 14. FIG. 4E is the same as FIG. 4D except for arrows of rotationR1 and R2 being removed and marking 38 being shown on proximal surfaceS1 within the bounds of indicator groove 14. FIG. 4F is an anteriorperspective view of resected tibia T of FIG. 4E showing proximal surfaceS1 including marking 38. FIG. 4F shows tibia T in the same orientationas FIG. 4E but without tibial spacer paddle 10.

Indicator groove 14 can align with the center of femur F, e.g. thecenter position between the medial and lateral condyles that iscoincident with femur axis AF. However, tibia T can be offset from theorientation of femur F such that the center of tibia T coincident withtibia axis AT is not aligned with the center of femur F. Tibial spacerpaddle 10 includes indicator groove 14 to allow a surgeon to visualizeand mark the center of femur F relative to the rotational position oftibia T in order to prepare tibia T and femur F for implantation ofprosthetic knee joint devices. An instrument or tool, such as a pen,Bovie, marker, scalpel or pick, can be inserted into indicator groove 14at bearing surface 18A and pushed through indicator groove 14 topenetrate beyond bearing surface 18B to contact proximal surface S1 oftibia T.

Marking 38, which can comprise a stripe of ink from a marker, a score inthe surface of proximal surface S1 from a pick, or the like, can providea fixed indicator on proximal surface S1 that points to where the centerof femur F aligns on tibia T. As such, the center of a prosthetic tibialimplant to be attached to proximal surface S1 of tibia T can be alignedwith marking 38 upon implantation. Thus, for example, bearing surfacesof the prosthetic tibial implant configured to mate with condylarsurfaces of a prosthetic femoral implant to be attached to femur F canbe oriented so that tibia T will have the natural rotational orientationwhen in full extension. When properly aligned in extension, theprosthetic femoral and tibial components will not resist the naturalorientation of the knee and joint pain and discomfort can be avoided.

Tibial spacer paddle 10 provides passive engagement with distal surfaceS2 of femur F. Tibial spacer paddle 10 is held in frictional engagementwith femur F via feet 12A and 12B. Other embodiments of tibial spacerpaddles can include features for providing positive engagement withfemur F.

Using the above-described device and procedures, a method fordetermining rotation between a femur and a tibia can include thefollowing steps: resect a femur and a tibia; position the tibia intoapproximately sixty degrees of flexion; insert a tibial spacer paddleinto an anterior opening between resections of the tibia and femur;engage medial and lateral paddle feet with posterior surfaces of thefemur so that the tibial spacer paddle is linked to the femur; extendthe tibia into extension so the tibia rotates against the tibial spacerpaddle; evaluate joint tension between the tibia and femur; inserttibial spacer paddles of different thicknesses into the anterior openinguntil a desired joint tension is achieved; making sure the medial andlateral paddle feet are engaged with posterior surface of femur, allowthe tibia to rotate into a natural position against the tibial spacerpaddle; identify a center of the femur at an indicator groove in thecenter of the tibial spacer paddle; and mark the center of the femur onthe tibia using the indicator groove.

FIG. 5 is a perspective view of tibial spacer paddle 110 havingalignment pegs 112A and 112B and indicator groove 114 disposed in spacerblock 116. FIG. 6 is a top view of tibial spacer paddle 110 of FIG. 5showing a location for indicator groove 114 relative to bearing surface118A. FIGS. 5 and 6 are discussed concurrently. Alignment pegs 112A and112B can be configured to provide positive engagement with a femoralprosthetic component attached to femur F.

Spacer block 116 can include first bearing surface 118A, second bearingsurface 118B, edge periphery surface 120, notch 122 and handle 124.Spacer block 116 can have a thickness between bearing surface 118A andbearing surface 118B that can differ in different embodiments in orderto trial the tension in the knee joint. Spacer block 116 can generallybe thinner than spacer block 16 due to spacer block 116 being configuredto mate with femoral component 240. Edge periphery surface 120 caninclude edge chamfers 126A and 126B. Notch 122 and indicator groove 114can extend into space block 116 to form first condylar portion 128A andsecond condylar portion 128B. Handle 124 can extend from edge peripherysurface 120 of spacer block 116 and can include first segment 130A andsecond segment 130B. Second segment 130B can comprise an elongate bodyhaving a central axis A3 that is configured to extend axially in thedirection of indicator groove 114.

Tibial spacer paddle 110 is configured similarly as tibial spacer paddle10 of FIGS. 1-3 except feet 12A and 12B are replaced by alignment pegs112A and 112B and chamfers 26A and 26B are replaced by edge chamfers126A and 126B. Additionally, posterior surfaces 36A and 36B are replacedby proximal surfaces 136A and 136B. All other elements are numberedsimilarly as 100 series numbers.

Alignment pegs 112A and 112B can be configured to hold spacer block 116into engagement with femoral implant 140 (FIG. 7) attached to a resectedfemur. Proximal surfaces 136A and 136B can protrude or project fromfirst bearing surface 118A so that pegs 112A and 112B are perpendicularto bearing surface 118A. However, in other examples, superior surfaces136A and 136B can extend at other angles relative to bearing surface118A for use with different femoral implants than the one shown in FIG.7. Thus, alignment pegs 112A and 112B can remain engaged with femoralcomponent 140 as the knee joint is moved through flexion. If desired, asurgeon can grasp handle 124 to facilitate engagement of spacer block116 and the femur. As the tibia moves from flexion to extension, thetibia can rotate against bearing surface 118B along vertical axis A4, asdescribed in greater detail with reference to FIGS. 8A-8C.

FIG. 7 is a perspective view of tibial spacer paddle 110 of FIG. 5 andfemoral component 140 engaged with alignment pegs 112A and 112B. Femoralcomponent 140 can comprise a femoral trial component that has distalsurfaces for engaging a tibial component and proximal surfaces forengaging a resected femur. A plurality of femoral components can beprovided with each of the femoral components having differentparameters, such as thicknesses, varus/valgus angles, etc., for trialingwith the anatomy of a patient. Femoral component 140 can be held inplace against femur F using bone cement, fasteners or by force fit withthe resected surfaces.

Femoral component 140 can comprise tibia-facing surface 142 formed alongthe outer periphery of femoral component 140 and can include lateralcondyle 144A and medial condyle 144B. Lateral condyle 144A and medialcondyle 144B can be configured for articulation with a prosthetic tibialcomponent. Femoral component 140 can include anterior flange 146 havingtrochlear groove 148. Trochlear groove 148 can extend from a generallyanterior and proximal starting point to a generally posterior and distalterminus. Trochlear groove 148 can form an anterior articular surface offemoral component 140 for articulation with a natural or prostheticpatella.

Femoral component 140 can define a transverse plane that can be a planetangent to distal-most points of lateral and medial condyles 144A and144B. Femoral component 140 can also define a coronal plane that can bea plane tangent to the posterior-most points of the lateral and medialcondyles 144A and 144B, when viewed from a lateral side of femoralcomponent 140, can be perpendicular to the transverse plane.

Femoral component 140 can include peg ports 150A and 150B that can beconfigured to engage alignment pegs 112A and 112B, respectively. Pegports 150A and 150B can be positioned in the transverse plane at thedistal-most points of lateral and medial condyles 144A and 144B,respectively.

Femoral component 140 can comprise femur-contacting portion 152 formedalong the inner periphery of femoral component 140 and can includedistal surface 154, first posterior surface 156A, second posteriorsurface 156B, angled anterior surface 158, first quarter surface 160Aand second quarter surface 160B. Distal surface 154, first posteriorsurface 156A, second posterior surface 156B, angled anterior surface158, first quarter surface 160A and second quarter surface 160B can beconfigured to align and mate with distal surface S2, first posteriorsurface S3A, second posterior surface S3B, angled anterior surface S4,first quarter surface S5A and second quarter surface SSB, respectively,of tibia T in FIGS. 4A-4F.

FIG. 8A is a perspective view of femoral component 140 of FIG. 7attached to resected femur F and tibial spacer paddle 110 of FIG. 5inserted between femoral component 140 and resected tibia T inapproximately sixty degrees of flexion.

With the knee joint in flexion, tibial spacer paddle 110 can be insertedinto an incision in an anterior portion of a knee joint so that handle124 can extend out of the incision. Second bearing surface 118B can bepositioned against resected proximal surface S1. Femur F and tibia T ofthe knee joint can be pushed or pulled apart, such as by using aretractor, to provide space for tibial spacer paddle 110. Edge chamfers126A and 126B can facilitate insertion of tibial spacer paddle 110 bynarrowing spacer block 116 and can eliminate sharp edges that couldpotentially interfere with or damage ligaments in the knee joint. Tibialspacer paddle 110 can be positioned so that alignment pegs 112A and 112Balign with peg ports 150A and 150B, respectively, in femoral component140.

FIG. 8B is a side view of femoral component 140 and tibial spacer paddle110 of FIG. 8A being moved toward full extension so that alignment pegs112A and 112B align with and are inserted into corresponding peg ports150A and 150B in femoral component 140. As tibia T moves into extension,indicated by arrow E, handle 124 can be used by a surgeon to guidealignment pegs 112A and 112B into peg ports 150A and 150B. As pegs 112Aand 112B engage femoral component 140, proximal surface S1 of tibia Tcan slide against bearing surface 118B and tibia T undergoes naturalrotation into extension.

FIG. 8C is a perspective view of femoral component 140 and tibial spacerpaddle 110 of FIG. 8B in full extension with tibia T rotated into anatural alignment position so that resected proximal surface S1 can bemarked at the indicator groove 114. With bearing surface 118A flushlyengaged with femoral component 140 and bearing surface 118B flushlyengaged with proximal surface S1 of tibia T, tibia T is free to rotateagainst spacer block 116, as shown by arrows of rotation R3 and R4. Pegs112A and 112B hold tibial spacer paddle 110 in positive engagement withfemoral component 140 at peg ports 150A and 150B. This engagement canreduce or eliminate slippage of tibial spacer paddle 110 relative tofemur F, which can help provide an accurate indication of the naturalrotational position of tibia T relative to femur F when in extension.Indicator groove 114 can be visible between lateral and medial condyles144A and 144B of femoral component 140 for both visual inspection andinsertion of a tool or instrument.

Marking 138, which can comprise a stripe of ink from a marker, a scorein the surface of proximal surface S1 from a pick, or the like, providesa fixed indicator on proximal surface S1 that points to where the centerof femur F aligns on tibia T. As such, the center of a prosthetic tibialimplant to be attached to proximal surface S1 of tibia T can be alignedwith marking 138 upon implantation.

Using the above-described device and procedures, a method fordetermining rotation between a femur and a tibia can include thefollowing steps: resect a femur and a tibia; position the tibia intoapproximately sixty degrees of flexion; attach a femoral component tothe resected femur; insert a tibial spacer paddle into an anterioropening between resections of the tibia and femur; guide tibial spacerpaddle pegs into corresponding ports in the femoral component to linkthe tibial spacer paddle and the femoral component; extend the tibiainto extension so the tibia rotates against the tibial spacer paddle;evaluate joint tension between the tibia and femur; insert tibial spacerpaddles of different thicknesses into the anterior opening until adesired joint tension is achieved; allow the tibia to rotate against thetibial spacer paddle into a natural position; identify a center of thefemur at an indicator groove in the center of the tibial spacer paddle;and mark the center of the femur on the tibia using the indicatorgroove.

FIG. 9A is a perspective view of tibial sizing system 210 comprisingprovisional component 212 and sizing plate 214 aligned for insertiononto resected tibia T. Provisional component 212 can include condylebearing surfaces (or articulating surfaces) 216A and 216B, an opposingengagement (bearing) surface 218, socket 220 and engagement tab 222.Engagement tab 222 can include body 224 and notch 226. Sizing plate 214can comprise bone-facing (bone-engaging) surface 228, engagement surface230, socket 232 and etch lines 234A and 234B. Sizing plate 214 isdiscussed further with reference to FIG. 9E. In examples, provisionalcomponent 212 can comprise a one-piece Tibial Articular SurfaceProvisional (TASP), commercially available from Zimmer Biomet under thePersona brand, modified to include engagement tab 222. In examples,sizing plate 214 can comprise a tibial sizing plate as described in U.S.Pat. No. 5,634,927 to Houston et al., which is assigned to Zimmer, Inc.,modified to include etch lines 234A and 234B. U.S. Pat. No. 5,634,927 toHouston et al. is hereby incorporated by this reference in its entiretyfor all purposes.

FIG. 9A also shows femoral component 240 attached to resected femur F.Femoral component 240 can be similar to that of femoral component 140 ofFIG. 7, except for the addition of pin port 262. All other elements arenumbered similarly as 200 series numbers. For example, femoral component240 can comprise tibia-facing surface 242 formed along the outerperiphery of femoral component 240, which can include lateral condyle244A and medial condyle 244B, anterior flange 246 having trochleargroove 248, and femur-contacting portion 252 formed along the innerperiphery of femoral component 240, which can include distal surface254, first posterior surface 256A, second posterior surface 256B, angledanterior surface 258, first quarter surface 260A and second quartersurface 260B.

Femoral component 240 can also include pin bore 262 for the reception ofpin 264. Pin 264, such as a trocar pin, can be inserted into pin bore262. Pin bore 262 can be positioned to align with engagement tab 222when the centers of femoral component 240 and provisional component 212are aligned.

Femoral component 240 can be attached to femur F in any suitable manner,as described above. Likewise, provisional component 212 can be attachedto sizing plate 214 in a releasable manner. For example, provisionalcomponent 212 can be snap fit into sizing plate 214, as described below.Sizing plate 214 is configured to slide against proximal surface S1 oftibia T. Because femoral components 240 and tibial provisional component214 can be configured as trialing components, femoral components 240 andprovisional component 214 can be removably attached to the respectivesurfaces.

In FIG. 9A, tibia T and femur F can be resected to have surfaces asdescribed with reference to FIG. 4A. Femoral component 240 can beattached to femur F and then tibial sizing system 210 can be inserted,as indicated by arrow I1, between femoral component 240 and resectedproximal surface S1 of tibia T.

FIG. 9B is perspective view of femoral component 240 and tibial sizingsystem 210 of FIG. 9A with tibial sizing system 210 inserted betweenfemoral component 240 and resected tibia T in extension. As shown, bothpin bore 262 and engagement tab 222 are positioned on the same side offemoral component 240 and tibial sizing system 210, respectively. Astibia T is moved into full extension, tibial sizing system 210 can bepositioned so that notch 226 can align with pin 264, as proximal surfaceS1 of tibia T rotates against bone-facing surface 228 of sizing plate214. With pin 2464 engaged with notch 226, provisional component 212 canbe swapped out for provisional components of similar construction, butwith different thicknesses. For example, the thickness between bearingsurfaces 216A and 216B and engagement surface 218 can be different indifferent embodiments of sizing plates 214. The different thicknessescan be used to set the desired ligament tension between tibia T andfemur F.

FIG. 9C is perspective view of femoral component 240 and tibial sizingsystem 210 of FIG. 9B with femur F in full extension and tibia T rotatedso pin 264 extending into femoral component 240 aligns with tab 222 ontibial provisional component 210. Once the desired tension is set, tibiaT and femur F can be set into extension so that pin 264 aligns withnotch 226. Tibia T can find a natural rotational position in extensionwith respect to femur F, as shown by arrows of rotation R5 and R6. Forexample, proximal surface S1 of tibia T can rotate against bone-facingsurface 228 of sizing plate 214.

FIG. 9D is a perspective view of femoral component 240 and tibial sizingsystem 210 of FIG. 9B with pin 264 extending along tab 222 and alignmentmarkings 266A and 266B on the tibia T. Etch lines 234A and 234B can bepositioned along tibia T adjacent proximal surface S1. Markings 266A and266B, which can comprise a stripe of ink from a pen, a Bovie, a marker,a score in the surface of proximal surface S1 from a pick, or the like,provides a fixed indicator on proximal surface S1 that points to wherethe center of femur F and a secondary reference point align on tibia T.For example, marking 266B can indicate the center of femur F and marking266A can be used to verify rotation of tibia T and provide a secondaryreference point. As such, the center of a prosthetic tibial implant tobe attached to proximal surface S1 of tibia T can be aligned withmarking 266B upon implantation and a secondary mark corresponding toetch line 234B on the prosthetic tibial implant can be aligned withmarking 266A.

FIG. 9E is a perspective view of resected tibia T of FIG. 9D showingsizing plate 214 of the tibial sizing system 210 disposed on theresected tibia surface T. Sizing plate 214 can include wall 268, keelsocket 270 and fixation bores 272. Fixation bores 272 can compriseopenings in engagement surface 230 into which fasteners can be insertedto retain sizing plate 214 against proximal surface S1 of tibia T. Keelsocket 270 can comprise an opening in engagement surface 230 into whicha fixation feature, such as a keel, of a prosthetic tibial component canbe inserted. Wall 268 can comprise a flange extending from engagementsurface 230 that can function to retain provisional component 212. Forexample, provisional component 212 can include corresponding features(e.g., cutback 290 and cutback 292 of FIG. 14) that allow provisionalcomponent 212 to be snap fit into wall 268. Etch lines 234A and 234B andmarkings 266A and 266B can be used to orient keel socket 270 relative toproximal surface S1 to provide rotational orientation of the prosthetictibial component relative to the mechanical axis (e.g., vertical axis A2of FIG. 1 or tibial axis AT of FIG. 4A) of tibia T. Further descriptionof sizing plate 214 can be found in the aforementioned '927 patent toHouston et al.

Using the above-described device and procedures, a method fordetermining rotation between a femur and a tibia can include thefollowing steps: resect a femur and a tibia; position the tibia intoapproximately sixty degrees of flexion; attach a femoral component tothe resected femur; insert a pin into the femoral component; connect atibial sizing plate to tibial provisional component; insert theconnected tibial sizing plate and tibial provisional component into ananterior opening between resections of the tibia and femur; extend thetibia into extension so the tibia rotates against the tibial sizingplate; guide the pin into a notch in the tibial provisional component tolink the tibial provisional component and the femoral component;evaluate joint tension between the tibia and femur; connect tibialprovisional components of different thicknesses to the tibial sizingplate until a desired joint tension is achieved; allow the tibia torotate against the tibial sizing plate into a natural position; identifya center of the femur at an indicator in the center of the tibial sizingplate; and mark the center of the femur on the tibia using theindicator.

FIG. 10 is a perspective view of another embodiment of tibial sizingsystem 210′ of FIG. 9A wherein provisional component 212′ and sizingplate 214′ are integrated into monolithic component 273. Monolithiccomponent 273 can function the same as the combination of provisionalcomponent 212 and sizing plate 214, except for being a single, unitarycomponent. Thus, a plurality of monolithic components 273 can beprovided with different thicknesses in order to trial the desiredligament tension between tibia T and femur F. Certain features can beeliminated from tibial sizing system 210′ for simplicity, such as socket232. Additionally, engagement surface 218 and engagement surface 230 canbe eliminated because monolithic component 273 is fused along thisplanar intersection as compared to tibial sizing system 210.

Using the above-described device and procedures, a method fordetermining rotation between a femur and a tibia can include thefollowing steps: resect a femur and a tibia; position the tibia intoapproximately sixty degrees of flexion; attach a femoral component tothe resected femur; insert a pin into the femoral component; insert atibial provisional component into an anterior opening between resectionsof the tibia and femur; extend the tibia into extension so the tibiarotates against the tibial provisional component; guide the pin into anotch in the tibial provisional component to link the tibial provisionalcomponent and the femoral component; evaluate joint tension between thetibia and femur; insert tibial provisional components of differentthicknesses into the anterior opening until a desired joint tension isachieved; allow the tibia to rotate against the tibial provisionalcomponent into a natural position; identify a center of the femur at anindicator in the center of the tibial provisional component; and markthe center of the femur on the tibia using the indicator.

FIG. 11 is a perspective view of femoral component 240 attached toresected femur F and tibial sizing system 410 comprising provisionalcomponent 212 and tibial plate 300 with pivot mount 302 (FIG. 12)inserted between femoral component 240 and resected tibia T. Provisionalcomponent 212 can include pivot port 274 (FIG. 14) that can receivepivot mount 302 such that provisional component 212 can rotate or pivotrelative to tibial plate 300.

Femur F and tibia T can be resected as described herein. Femoralcomponent 240 can be configured the same as femoral component 240 ofFIGS. 9A-9D to include pin bore 262 for the reception of pin 264.Provisional component 212 can be similar to that of provisionalcomponent 212 of FIGS. 9A-9D, except for the addition of pivot port 274and etch lines 278A and 278B. All other elements are numbered the same.

As mentioned, pivot port 274 and pivot mount 302 can connect in arotational engagement. Tibial plate 300 can engage tibia T in a freemanner and provisional component 212 can slide against tibial plate 300to facilitate determination of the natural rotation of tibia T.

FIG. 12 is a perspective view of tibial plate 300 with pivot mount 302of FIG. 11 that can be configured to extend from bearing surface 304.Additionally, tibial plate 300 can include bone-facing (bone-engaging)surface 306 and edge periphery region 308, which can connect bearingsurface 304 and bone-facing surface 306. Pivot mount 302 can comprise acylindrical peg extending perpendicularly from bearing surface 304.Bearing surface 304 can have a smooth finish to reduce frictionalengagement with engagement surface 218. For example, tibial plate 300can be finished, such as via a polishing operation, to reduce thecoefficient of friction of bearing surface 304.

FIG. 13 is a top perspective view of provisional component 212 of FIG.11 showing the construction of engagement tab 222 and socket 232.Engagement tab 222 can include body 224 and notch 226. Socket 232 caninclude bores 284A and 284B and through-port 286.

Notch 222 can include bottom portion 280 and sidewalls 282A and 282B.Notch 222 can be configured to receive a pin, rod or other memberextending form femoral component 240, such as pin 264. For example,bottom portion 280 can form a semi-circular wall. Pin 264 can becylindrical and bottom portion 280 can be configured to have a matchingdiameter to flushly receive pin 264. Sidewalls 282A and 282B can extendfrom bottom portion 280 upward away from the remainder of body 224 andthe distance between sidewalls 282A and 282B can increase as sidewalls282A and 282B extend further away from bottom portion 280. In otherwords, portions of body 224 forming sidewalls 282A and 282B can taper assidewalls 282A and 282B extend away from bottom portion 280. As such,the wider portion of notch 222 in the proximal direction can guide pin264 into engagement with bottom portion 280 as tibia T is moved intofull extension.

Socket 232 can be configured to receive a tool to facilitate insertionand removal of provisional component 212. In examples, bores 284A and284B can be configured to receive pins of a tibial insertion handle.Through-port 286 can thereafter be configured to receive a tooth of aspring-loaded slide on the handle that locks the handle to provisionalcomponent 212. In examples, socket 232 can be configured to operate withthe pins and the tooth described in U.S. Pat. No. 8,603,101 to Claypoolet al., which is hereby incorporated by this reference in its entiretyfor all purposes.

FIG. 14 is a bottom perspective view of provisional component 212 ofFIG. 11 showing engagement surface 218, pivot port 274, anterior cutback290 and posterior cutback 292. Engagement surface (or bearing surface)218 can be smooth to slide against bearing surface 304. Pivot port 274can be located in engagement surface 218 and can be positioned to alignwith pivot mount 302. Pivot port 274 can comprise a cylindrical bore toreceive pivot mount 302. Anterior cutback 290 and posterior cutback 292can be recesses into engagement surface 218 that extend all the way toedge periphery surface 294. Edge periphery surface 294 can connectengagement surface 218 and condyle bearing surfaces 216A and 216B. Edgeperiphery surface 294 can also include etch lines 278A and 278B.Anterior cutback 290 and posterior cutback 292 can be configured toengage wall 268 of sizing plate 214 (FIG. 9E) to assist in retainingprovisional component 212 in engagement with sizing plate 214.Additionally, anterior cutback 290 and posterior cutback 292 can allowengagement surface 218 to sit down into wall 268.

FIG. 15A is a perspective view of femoral component 240 of FIG. 11attached to resected femur F and tibial sizing system 410 exploded fromresected tibia T. As shown by arrow C1, tibial plate 300 can beconnected to provisional component 212 by inserting pivot mount 302 intopivot port 274 (FIG. 14) to form assembled tibial sizing system 410. Abiocompatible lubricant can be positioned between tibial plate 300 andprovisional component 212 to facilitate relative rotation therebetween.As shown by arrow C2, the assembled tibial sizing system 210 can beinserted into a knee joint between tibia T and femur F so that surface306 faces proximal surface S1 of tibia T. As such, bearing surfaces 216Aand 216B can face toward femoral component 240. Different provisionalcomponents 212 of different thicknesses can be trialed between tibia Tand femur F to find the proper tension.

FIG. 15B is a perspective view of assembled tibial sizing system 410 ofFIG. 15A inserted between femoral component 240 and resected tibia T.Pin 264 can be inserted into pin bore 262 in femoral component 240. Withpin 264 engaged with engagement tab 222 to lock relative rotationbetween femoral component 240 and provisional component 212, tibia T canrotate into natural alignment, as shown by arrows of rotation R7 and R8,as proximal surface S1 rotates against surface 306. Attachment of tibialplate 300 to provisional component 212 via pivot mount 302 allows tibialplate 300 to rotate with tibia T while sliding against proximal surfaceS1 to provide a better indication of the natural rotational position oftibia T relative to femur F when in extension. For example, tibia T canbe less encumbered by resistance from tibial sizing system 410 tofacilitate true rotation of tibia T.

FIG. 15C is a perspective view of tibia T of FIG. 15B in full extensionso that pin 264 is fully seated in engagement tab 222 and resected tibiaT is marked with alignment markings 310A and 310B. As with markings 266Aand 266B, markings 310A and 310B can provide reference marks foraligning with features of a prosthetic tibial component that providerotational alignment of the prosthetic tibial component so that theprosthetic tibial component will not stress the knee joint when inextension, e.g., tibia T will find its natural rotational positionwithout pushback from the prosthetic tibial component against aprosthetic femoral component. In various examples, tibial plate 300 caninclude cut-outs or windows (not shown) that permit proximal surface S1to be viewed through tibial plate 300.

Using the above-described device and procedures, a method fordetermining rotation between a femur and a tibia can include thefollowing steps: resect a femur and a tibia; position the tibia intoapproximately sixty degrees of flexion; attach a femoral component tothe resected femur; insert a pin into the femoral component; connect atibial plate to tibial provisional component at a pivot coupling; insertthe coupled tibial plate and tibial provisional component into ananterior opening between resections of the tibia and femur; extend thetibia into extension so the tibia rotates against the tibial plate;guide the pin into a notch in the tibial provisional component to linkthe tibial provisional component and the femoral component; evaluatejoint tension between the tibia and femur; connect tibial provisionalcomponents of different thicknesses to the tibial plate until a desiredjoint tension is achieved; allow the tibia to rotate against the tibialplate into a natural position while the tibial plate rotates against thetibial provisional component; identify a center of the femur at anindicator in the center of the tibial provisional component; and markthe center of the femur on the tibia using the indicator.

FIG. 16 is a top perspective view of another embodiment of provisionalcomponent 212 of FIGS. 13 and 14, but without alignment tab 222. FIG. 17is a bottom perspective view of the embodiment of provisional component212 of FIG. 16. Alignment tab 222 can be omitted to simplify theconstruction of provisional component 212 and to simplify the method oftrialing the tibial component. In some circumstances, it may besufficient to determine the natural rotational position of tibia Twithout preventing relative rotation between femoral component 240 andprovisional component 212. For example, the frictional engagementbetween lateral condyle 244A and medial condyle 244B with bearingsurface 216A and bearing surface 216B, respectively, may be sufficientto immobilize provisional component 212. In examples, bearing surfaces216A and 216B can be provided with texturing, such as knurling,pyramids, spikes or other projections to facilitate linked rotation.

Using the above-described device and procedures, a method fordetermining rotation between a femur and a tibia can include thefollowing steps: resect a femur and a tibia; position the tibia intoapproximately sixty degrees of flexion; attach a femoral component tothe resected femur; connect a tibial plate to tibial provisionalcomponent at a pivot coupling; insert the coupled tibial plate andtibial provisional component into an anterior opening between resectionsof the tibia and femur; extend the tibia into extension so the tibiarotates against the tibial plate; evaluate joint tension between thetibia and femur; connect tibial provisional components of differentthicknesses to the tibial plate until a desired joint tension isachieved; allow the tibia to rotate against the tibial plate into anatural position while the tibial plate rotates against the tibialprovisional component; identify a center of the femur at an indicator inthe center of the tibial provisional component; and mark the center ofthe femur on the tibia using the indicator.

VARIOUS NOTES & EXAMPLES

Example 1 can include or use subject matter such as a tibial spacerpaddle that can comprise: a spacer block that can comprise: a firstbearing surface, a second bearing surface disposed opposite the firstbearing surface, and an edge periphery region connecting the firstbearing surface and the second bearing surface; a first foot extendingfrom the first bearing surface at the edge periphery region; a secondfoot extending from the first bearing surface at the edge peripheryregion spaced from the first foot; a first alignment chamfer extendinginto the edge periphery region and the second bearing surface oppositethe first foot; a second alignment chamfer extending into the edgeperiphery region and the second bearing surface opposite the secondfoot; an alignment slot extending into the edge periphery regionopposite the first and second feet; and a handle extending from thespacer block.

Example 2 can include, or can optionally be combined with the subjectmatter of Example 1, to optionally include an alignment slot that can bepositioned between the first and second feet.

Example 3 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 1 or 2 to optionallyinclude a notch extending into the edge periphery region between thefirst and second alignment chamfers.

Example 4 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 1 through 3 to optionallyinclude a notch that can align with the alignment slot on opposite sidesof the spacer block.

Example 5 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 1 through 4 to optionallyinclude a notch and an alignment slot that can separate the firstbearing surface into first and second condylar surfaces.

Example 6 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 1 through 5 to optionallyinclude first and second alignment chamfers that can be disposed atapproximately forty-five degrees to the first and second bearingsurfaces.

Example 7 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 1 through 6 to optionallyinclude an alignment slot that can be tapered between the first bearingsurface and the second bearing surface.

Example 8 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 1 through 7 to optionallyinclude a handle that can extend from the edge periphery regionproximate the alignment slot.

Example 9 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 1 through 8 to optionallyinclude a handle that can comprise: a curved segment extending from theedge periphery region; and a straight segment connected to the curvedsegment.

Example 10 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 1 through 11 to optionallyinclude a curved segment that can position the straight segment to alignwith the alignment slot.

Example 11 can include or use subject matter such as a tibial spacersystem that can comprise: a spacer block that can comprise: a firstbearing surface, a second bearing surface disposed opposite the firstbearing surface, and an edge periphery region connecting the firstbearing surface and the second bearing surface; a first peg extendingfrom the first bearing surface; a second peg extending from the firstbearing surface spaced from the first peg; an alignment slot extendinginto the edge periphery region; and a handle extending from the spacerblock.

Example 12 can include, or can optionally be combined with the subjectmatter of Example 11, to optionally include an alignment slot that canbe positioned between the first and second pegs.

Example 13 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 11 or 12 to optionallyinclude a notch extending into the edge periphery region between thefirst and second pegs.

Example 14 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 11 through 13 to optionallyinclude a notch that can align with the alignment slot on opposite sidesof the spacer block.

Example 15 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 11 through 14 to optionallyinclude a notch and an alignment slot that can separate the firstbearing surface into first and second condylar surfaces.

Example 16 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 11 through 15 to optionallyinclude a first peg and the a second peg that can be spaced from theedge periphery region.

Example 17 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 11 through 16 to optionallyinclude an alignment slot that can be tapered between the first bearingsurface and the second bearing surface.

Example 18 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 11 through 17 to optionallyinclude a handle that can extend from the edge periphery regionproximate the alignment slot.

Example 19 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 11 through 18 to optionallyinclude a handle that can comprise: a curved segment extending from theedge periphery region; and a straight segment connected to the curvedsegment; wherein the curved segment positions the straight segment toalign with the alignment slot.

Example 20 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 11 through 19 to optionallyinclude a femoral component that can comprise: a first condylar body; asecond condylar body connected to the first condylar body; a firstalignment port located in the first condylar body and configured toalign with the first peg; and a second alignment port located in thesecond condylar body and configured to align with the second peg.

Example 21 can include or use subject matter such as a tibial spacersystem that can comprise: a provisional component that can comprise: abody, an articulating surface positioned on the body configured toengage condylar surfaces of a femoral component, and an alignment tabextending from the body; and a sizing extension extending from the bodyopposite the articulating surface, the sizing extension can comprise: abone engagement surface, an edge periphery region extending from thebone engagement surface, and a first alignment indicator located on theedge periphery region of the sizing extension.

Example 22 can include, or can optionally be combined with the subjectmatter of Example 21, to optionally include a femoral component, thefemoral component can comprise: a first condylar body; a second condylarbody connected to the first condylar body; and a pin port extending intothe femoral component, the pin port configured to align with thealignment tab.

Example 23 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 21 or 22 to optionallyinclude a pin configured to be inserted into the pin port.

Example 24 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 21 through 23 to optionallyinclude an alignment tab that can include a notch configured to receivethe pin when the femoral component is located in an extension positionrelative to the articulating surface.

Example 25 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 21 through 24 to optionallyinclude a body of the provisional component and the sizing extension canbe integrated into a monolithic component.

Example 26 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 21 through 25 to optionallyinclude a sizing extension that can comprise a plate attachable to thebody of the provisional component.

Example 27 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 21 through 26 to optionallyinclude a plurality of provisional components, wherein each of theplurality of provisional components includes a different thickness.

Example 28 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 21 through 27 to optionallyinclude a second alignment indicator located on the edge peripheryregion of the sizing extension; wherein the first alignment indicator islocated proximate a center of a posterior portion of the edge peripheryregion and the second alignment indicator is spaced from the firstalignment indicator.

Example 29 can include or use subject matter such as a tibial spacersystem that can comprise: a provisional component that can comprise: anarticulating surface configured to engage condylar surfaces of a femoralcomponent, a first bearing surface disposed opposite the articulatingsurface, and a first edge periphery region connecting the articulatingsurface and the first bearing surface; a trial bearing that cancomprise: a bone engagement surface, a second bearing surface disposedopposite the bone engagement surface, and a second edge periphery regionconnecting the bone engagement surface and the second bearing surface;and a pivot coupling connecting the first bearing surface and the secondbearing surface configured to permit the trial bearing to rotaterelative to the provisional component.

Example 30 can include, or can optionally be combined with the subjectmatter of Example 29, to optionally include a pivot coupling that cancomprise: a peg extending from the second bearing surface; and a socketextending into the first bearing surface; wherein the peg is positionedto align with the socket when the second edge periphery region issubstantially aligned with the first edge periphery region.

Example 31 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 29 or 30 to optionallyinclude a peg that is positioned on the second bearing surface so as tobe co-axial with a mechanical axis of the tibia; and a socket that ispositioned on the first bearing surface so as to be co-axial with themechanical axis of the tibia.

Example 32 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 29 through 31 to optionallyinclude a provisional component that can further comprise an alignmenttab extending from the first edge periphery region.

Example 33 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 29 through 32 to optionallyinclude a femoral component, the femoral component can comprise: a firstcondylar body; a second condylar body connected to the first condylarbody; and a pin port extending into the femoral component, the pin portconfigured to align with the alignment tab.

Example 34 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 29 through 33 to optionallyinclude a pin configured to be inserted into the pin port.

Example 35 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 29 through 34 to optionallyinclude a tab that can include a notch configured to receive the pinwhen the femoral component is located in an extension position relativeto the articulating surface.

Example 36 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 29 through 35 to optionallyinclude a first edge periphery region that can include a first alignmentindicator.

Example 37 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 29 through 36 to optionallyinclude a second alignment indicator located on the first edge peripheryregion of the provisional component; wherein the first alignmentindicator is located proximate a center of a posterior portion of thefirst edge periphery region and the second alignment indicator is spacedfrom the first alignment indicator.

Example 38 can include, or can optionally be combined with the subjectmatter of one or any combination of Examples 29 through 37 to optionallyinclude a plurality of provisional components, wherein each of theplurality of provisional components includes a different thickness.

Each of these non-limiting examples can stand on its own, or can becombined in various permutations or combinations with one or more of theother examples.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In the event of inconsistent usages between this document and anydocuments so incorporated by reference, the usage in this documentcontrols.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription as examples or embodiments, with each claim standing on itsown as a separate embodiment, and it is contemplated that suchembodiments can be combined with each other in various combinations orpermutations. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

The claimed invention is:
 1. A tibial spacer paddle comprising: a spacer block comprising: a first bearing surface; a second bearing surface disposed opposite the first bearing surface; and an edge periphery region connecting the first bearing surface and the second bearing surface; a first foot extending from the first bearing surface at the edge periphery region; a second foot extending from the first bearing surface at the edge periphery region spaced from the first foot; a first alignment chamfer extending into the edge periphery region and the second bearing surface opposite the first foot; a second alignment chamfer extending into the edge periphery region and the second bearing surface opposite the second foot; an alignment slot extending into the edge periphery region opposite the first and second feet; and a handle extending from the spacer block.
 2. The tibial spacer paddle of claim 1, wherein the alignment slot is positioned between the first and second feet.
 3. The tibial spacer paddle of claim 1, further comprising a notch extending into the edge periphery region between the first and second alignment chamfers.
 4. The tibial spacer paddle of claim 3, wherein the notch aligns with the alignment slot on opposite sides of the spacer block.
 5. The tibial spacer paddle of claim 4, wherein the notch and the alignment slot separate the first bearing surface into first and second condylar surfaces.
 6. The tibial spacer paddle of claim 1, wherein the first and second alignment chamfers are disposed at approximately forty-five degrees to the first and second bearing surfaces.
 7. The tibial spacer paddle of claim 1, wherein the alignment slot is tapered between the first bearing surface and the second bearing surface.
 8. The tibial spacer paddle of claim 1, wherein the handle extends from the edge periphery region proximate the alignment slot.
 9. The tibial spacer paddle of claim 8, wherein the handle comprises: a curved segment extending from the edge periphery region; and a straight segment connected to the curved segment.
 10. The tibial spacer paddle of claim 9, wherein the curved segment positions the straight segment to align with the alignment slot.
 11. A tibial spacer system comprising: a spacer block comprising: a first bearing surface; a second bearing surface disposed opposite the first bearing surface; and an edge periphery region connecting the first bearing surface and the second bearing surface; a first peg extending from the first bearing surface; a second peg extending from the first bearing surface spaced from the first peg; an alignment slot extending into the edge periphery region; and a handle extending from the spacer block.
 12. The tibial spacer system of claim 11, wherein the alignment slot is positioned between the first and second pegs.
 13. The tibial spacer system of claim 11, further comprising a notch extending into the edge periphery region between the first and second pegs.
 14. The tibial spacer system of claim 13, wherein the notch aligns with the alignment slot on opposite sides of the spacer block.
 15. The tibial spacer system of claim 14, wherein the notch and the alignment slot separate the first bearing surface into first and second condylar surfaces.
 16. The tibial spacer system of claim 11, wherein the first peg and the second peg are spaced from the edge periphery region.
 17. The tibial spacer system of claim 11, wherein the alignment slot is tapered between the first bearing surface and the second bearing surface.
 18. The tibial spacer system of claim 11, wherein the handle extends from the edge periphery region proximate the alignment slot.
 19. The tibial spacer system of claim 18, wherein the handle comprises: a curved segment extending from the edge periphery region; and a straight segment connected to the curved segment; wherein the curved segment positions the straight segment to align with the alignment slot.
 20. The tibial spacer system of claim 11, further comprising: a femoral component comprising: a first condylar body; a second condylar body connected to the first condylar body; a first alignment port located in the first condylar body and configured to align with the first peg; and a second alignment port located in the second condylar body and configured to align with the second peg. 